Rystiggo (rozanolixizumab-noli) is a subcutaneous (under the skin) injection for infusion that may be used to improve muscle weakness in adults with generalized myasthenia gravis who are anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody positive.

Generalized myasthenia gravis is a rare disease characterized by severe, life-threatening, muscular weakness that can cause symptoms such as difficulty breathing, double vision, drooping eyelids, and difficulty swallowing, chewing, and talking. The global prevalence is 100–350 cases per every 1 million people and it can occur in any race, gender or age.

Rystiggo (rozanolixizumab-noli) works by attaching to and blocking a protein called the neonatal Fc receptor (FcRn) which is involved in regulating levels of autoantibodies. Autoantibodies are produced by the immune system of people with generalized myasthenia gravis that damage acetylcholine receptors, which prevents acetylcholine from activating them. For a muscle to contract, acetylcholine released from the end of a nerve must be able to attach to acetylcholine receptors.  If autoantibodies damage these receptors, then the muscles are not able to contract as well as normal, leading to muscle weakness and difficulty moving. Rozanolixizumab-noli is a humanized IgG4 monoclonal antibody.

Rystiggo was FDA approved on June 27, 2023. It is the first treatment to be approved for the two most common subtypes of gMG in adults, anti-AChR and anti-MuSK antibody-positive gMG.

Rystiggo can increase your risk of infection and should not be administered if you currently have an infection. Call your doctor at once if you develop fever, chills, sore throat, body aches, unusual tiredness, loss of appetite, bruising, or bleeding.

Serious events of aseptic meningitis have been reported. Your doctor will monitor you for symptoms and initiate treatment if necessary.

Hypersensitivity reactions including angioedema and rash have occurred in some patients treated with Rystiggo. Your doctor will monitor you during your infusion for hypersensitivity reactions. Seek medical attention if you develop any allergic-type reactions following the infusion.

Rystiggo will be administered by your healthcare provider in their clinic. It will be given subcutaneously (this means under the skin) using an infusion pump in the lower right or lower left part of your abdominal area but not close to your navel.

The time the infusion takes depends on your dose of medicine, but it is given at a rate of 20mL/hour which means most infusions will take 1 to 2 minutes. You will be monitored for hypersensitivity reactions during the infusion and for at least 15 minutes afterward.

Rystiggo is usually administered as a treatment cycle that is given once a week for 6 weeks. The usual dosage depends on body weight:

• Less than 50kg: 420mg (3mL to be infused [1 minute])
• 50kg to less than 100kg: 560mg (4mL to be infused [1.3 minutes])
• 100kg or more: 840mg (6mL to be infused [2 minutes]).

The line should not be flushed after use as the volume of the infusion has been adjusted to account for losses in the line.

The need for subsequent treatment cycles depends on the response. The safety of initiating subsequent cycles sooner than 63 days from the start of the previous treatment cycle has not been established.

Rystiggo will be administered by your healthcare provider in their clinic. It will be given subcutaneously (this means under the skin) using an infusion pump in the lower right or lower left part of your abdominal area but not close to your navel.

The time the infusion takes depends on your dose of medicine, but it is given at a rate of 20mL/hour which means most infusions will take 1 to 2 minutes. You will be monitored for hypersensitivity reactions during the infusion and for at least 15 minutes afterward.

Rystiggo is usually administered as a treatment cycle that is given once a week for 6 weeks. The usual dosage depends on body weight:

• Less than 50kg: 420mg (3mL to be infused [1 minute])
• 50kg to less than 100kg: 560mg (4mL to be infused [1.3 minutes])
• 100kg or more: 840mg (6mL to be infused [2 minutes]).

The line should not be flushed after use as the volume of the infusion has been adjusted to account for losses in the line.

The need for subsequent treatment cycles depends on the response. The safety of initiating subsequent cycles sooner than 63 days from the start of the previous treatment cycle has not been established.

To make sure Rystiggo is safe for you, tell your doctor if you:

• Currently have an infection or have had any infections recently
• Have received or are scheduled to receive a vaccine (immunization). All age-appropriate immunizations should be completed before starting Rystiggo. Administration of live or live-attenuated vaccines is not recommended during treatment
• Are pregnant or plan to become pregnant
• Are breastfeeding or plan to breastfeed.

Based on animal data, Rystiggo may cause fetal harm. It is unknown if Rystiggo passes into breast milk.

If a scheduled dose is missed, Rystiggo may be administered up to 4 days after the scheduled time point. Thereafter, the original dosing schedule should be resumed until the treatment cycle is completed. Call your doctor for instructions if you miss an appointment for your infusion.

Because Rystiggo is administered by a healthcare provider, it is unlikely that you will overdose.

You should avoid receiving live vaccines while you are being treated with this medicine.

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

• Signs of infection--fever, chills, sore throat, body aches, unusual tiredness, loss of appetite, bruising, or bleeding.

Common Rystiggo side effects include:

• Headache
• Infections including upper respiratory tract infections
• Diarrhea
• Fever
• Hypersensitivity reactions
• Nausea
• Administration site reactions
• Abdominal pain
• Joint pain.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Care should be taken when using Rystiggo with other medications that bind to the human neonatal Fc receptor (FcRn) (such as immunoglobulin products, monoclonal antibodies, or antibody derivates containing the human Fc domain of the IgG subclass) because it may reduce the effectiveness of these medications.

Rystiggo may have interactions with other prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use, and when you start, stop, or change a dose of any medicine.